Soundscope Pro: Spectrum RTA

Soundscope Pro is a real-time audio analyzer with two faces, and one purchase covers iPhone, iPad and Apple Watch. No subscription, no ads, no account, and no audio ever leaves your device.

TWO WAYS TO SEE SOUND
• Analog: a third-octave analyzer built like a piece of hardware. Thirty-one columns on the IEC center frequencies from 20 Hz to 20 kHz, each one a ladder of discrete LED segments running green, yellow, orange and red, with a peak-hold segment that falls slowly. Slow averaging to start with, so the face swings the way a rack unit does.
• Precision: a clean laboratory display. Octave, 1/3-octave or 1/6-octave bars with thin peak caps, the fine FFT spectrum drawn over them as a smooth curve with a soft fill, a logarithmic frequency axis gridded at 20, 50, 100, 200 and 500 Hz and 1, 2, 5, 10 and 20 kHz, and a labelled dB grid.

READ THE NUMBERS
• Dominant frequency and its nearest note.
• The loudest band, and the overall level of everything on screen.
• Touch and drag anywhere on the precision graph for a cursor: frequency, note and level at the point under your finger.

THE CONTROLS YOU EXPECT
• A, C and Z frequency weighting.
• Fast or slow averaging.
• Freeze holds a measurement still; the peak hold can be reset at any time.
• An adjustable dB window, moved from either end.

ON APPLE WATCH
The watch app runs on its own, with the same two faces, one per vertical page. Tap to reset the peaks, turn the Digital Crown to move the dB window, and read the dominant frequency and its note under the graph.

MADE FOR REAL WORK
• External audio interfaces and measurement microphones are supported; choose the input in Settings.
• Import your microphone's calibration file and the correction curve is applied to every band and to the fine spectrum.
• Set an SPL offset against a calibrator or a reference meter.
• A dark interface designed for stages and studios, with full light mode for daylight.
• On iPad and in landscape the graph takes the whole screen, with the controls in a column beside it.

A NOTE ON ACCURACY
Phones and watches are not certified sound level meters. Without calibration, absolute levels are indicative; relative readings — which band is loudest, how far one sits above another, where a room rings — are dependable. With a calibrated measurement microphone and an SPL offset Soundscope Pro becomes a trustworthy companion, but it does not replace a certified Class 1 or Class 2 instrument where regulations require one.